Rasmus (and SkengD a little bit LOL) - I am by no means a car setup expert, but I can offer a little help (I hope)...
The setup with these little cars is not quite as important as it is with bigger faster cars, consentrate on practicing until you get to the point where you notice tiny changes to setup.
Set your gearing to have a top speed of about 200kph or 125mph
Set your suspension up so that the front is a little harder than the rear
Try to touch the apex of each corner and get the maximum exit speed possible. Try to follow the lines driven by the faster drivers and don't worry if you come last (or close to last) because at the next event, you will get to drive with 425pp!